Series resonant converter: state-plane analysisECEN5817 Lecture 22

ECEN 58171

Below resonance operation (k = 1, CCM*)definition of subintervals Q1, D1, Q2, D2

vs(t)

Vg

vs1(t)Textbook Fig.19.25, waveforms based on sinusoidal approximation

ts

– Vg

is(t)

Ts

2tt

Ts

2+ t

Q1

Q4

D1

D4

Q2

Q3

D2

D3

Conductingdevices:

ECEN 58172

Q4 4 Q3 3

“Hard”turn-on of

Q1, Q4

“Soft”turn-off of

Q1, Q4

“Hard”turn-on of

Q2, Q3

“Soft”turn-off of

Q2, Q3

*The operating mode notation will be explained later

Subinterval Q1: iL > 0, conducting devices: Q1, Q4, D5, D8

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Subinterval D1*: iL < 0, conducting devices: D1, D4, D6, D7

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*Error in Fig.4.3 of Ch.4 typed notes: MT = 1+M, not 1-M

Subinterval Q2: iL < 0, conducting devices: Q2, Q3, D6, D7

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Subinterval D2: iL > 0, conducting devices: D2, D3, D5, D8

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State plane for SRC (below resonance, k = 1, CCM)

ECEN 58177

Typical SRC waveforms (below resonance, k=1, CCM)

ECEN 58178

Capacitor charge arguments

ECEN 58179

SRC Steady-State Solution (below resonance, k=1, CCM)

Radius MA1

Radius MA2

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SRC Steady-State Solution (below resonance, k=1, CCM)

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SRC Steady-State Solution (below resonance, k=1, CCM)

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SRC Steady-State Solution (below resonance, k=1, CCM)

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SRC Steady-State Characteristics (below resonance, k=1, CCM)

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SRC Steady-State Output-Plane Characteristics (below resonance, k=1, CCM)

Special cases: discussion

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SRC Steady-State Control-Plane Characteristics (below resonance, k=1, CCM)

ECEN 581716

SRC Steady-State Control-Plane Characteristics (below resonance, k=1, CCM)

ECEN 581717